Problem: The following formula is used in economics to find a company's net income $N$, where $P$ is the sales price, $V$ is the variable cost per unit, $S$ is the sales volume, and $F$ are fixed costs. $N = S\cdot (P-V)-F$ Rearrange the formula to highlight the sales volume. $S=$
Answer: Formulas may contain multiple variables, along with known numbers and letters that stand for known constants like $\pi$. We can highlight a certain variable in the formula by treating the formula as an equation where we want to solve for that variable. In this case, we need to solve the equation $N = S\cdot (P-V)-F$ for $S$. $\begin{aligned} N&= S\cdot (P-V)-F \\\\ N+F&= S\cdot (P-V) \\\\ \dfrac{N+F}{P-V}&=S \end{aligned}$ This is the result of rearranging the formula to highlight the sales volume: $S=\dfrac{N+F}{P-V}$